Dataset on the use of MGIDI index in screening drought-tolerant wild wheat accessions at the early growth stage

The dataset herein indicated the novelty of the article entitled “Dataset on the use of MGIDI in screening drought-tolerant wild wheat accessions at the early growth stage”. Data were gathered during 2018–2019 on a set of wild wheat germplasm under two control and water deficit stress conditions. One hundred and forty-six accessions belonging to Ae. tauschii, Ae. cylindrica, and Ae. crassa were assessed under optimal glasshouse conditions to screen the drought-tolerant samples at the early growth stage. Nine drought tolerance and susceptibility indices along with the multi-trait genotype-ideotype distance index (MGIDI) were used to visualize the dataset. The obtained data can highlight the potential of the MGIDI index in accelerating screening of a large number of plant materials using multiple traits or selection indices in crop breeding programs, especially at the early growth stage.

Assessment of genetic diversity among Iranian Aegilops triuncialis accessions using ISSR, SCoT, and CBDP markers

BACKGROUND

Crop wild relatives (CWRs) are commonly used as a suitable genetic reservoir for plant breeding. They can be used for enhancing the tolerance of plant varieties to biotic and abiotic stresses. Studying the genetic diversity of related wheat species in Iran could be useful to improve different traits of bread wheat, since the country is one of the major centers of genetic diversity and distribution of Aegilops species. Therefore, the aim of the present study was to determine the relationship among 48 Aegilops triuncialis accessions using three DNA marker systems, including start codon targeted (SCoT), CAAT box-derived polymorphism (CBDP), and inter-simple sequence repeat (ISSR) markers.

RESULTS

A total of 359 amplified DNA fragments were generated using 13 CBDP, 14 SCoT, and 16 ISSR primers that produced 96, 147, and 152 bands, respectively. The discriminating power of the three markers was assessed using polymorphism information content (PIC), marker index (MI), and resolving power (Rp). The mean values of PIC for ISSR, SCoT, and CBDP markers were 0.3, 0.26, and 0.34, respectively, indicating the efficiency of the three markers in detecting polymorphism among the studied accessions. ISSR markers had the highest values of MI, Rp, and polymorphism percentage as compared to SCoT and CBDP markers. Based on the Shannon index and heterozygosity values, genetic diversity in the Alborz population was more than in other populations. The accessions were classified into six, five, and five groups based on ISSR, SCoT, and CBDP using the UPGMA method. According to the results of cluster and PCoA analyses, the variation patterns corresponded with the geographical distribution of the Ae. triuncialis accessions.

CONCLUSIONS

The three markers provided a comprehensive pattern of the genetic diversity among the Iranian Ae. triuncialis accessions. This information could allow for a future insight into wheat breeding programs.

Phenological, morpho-physiological and proteomic responses of Triticum boeoticum to drought stress

Drought is the most important abiotic stress limiting wheat production worldwide. Triticum boeoticum, as wild wheat, is a rich gene pool for breeding for drought stress tolerance. In this study, to identify the most drought-tolerant and susceptible genotypes, ten T. boeoticum accessions were evaluated under non-stress and drought-stress conditions for two years. Among the studied traits, water-use efficiency (WUE) was suggested as the most important trait to identify drought-tolerant genotypes. According to the desirable and undesirable areas of the bi-plot, Tb5 and Tb6 genotypes were less and more affected by drought stress, respectively. Therefore, their flag-leaves proteins were used for two-dimensional gel electrophoresis. While, Tb5 contained a high amount of yield, yield components, and WUE, Tb6 had higher levels of water use, phenological related traits, and root related characters. Of the 235 spots found in the studied accessions, 14 spots (11 and 3 spots of Tb5 and Tb6, respectively) were selected for sequencing. Of these 14 spots, 9 and 5 spots were upregulated and downregulated, respectively. The identified proteins were grouped into six functional protein clusters, which were mainly involved in photosynthesis (36%), carbohydrate metabolism (29%), chaperone (7%), oxidation and reduction (7%), lipid metabolism and biological properties of the membrane (7%) and unknown function (14%). We report for the first time that MICP, in the group of lipid metabolism proteins, was significantly changed into wild wheat in response to drought stress. Maybe, the present-identified proteins could play an important role to understand the molecular pathways of wheat drought tolerance. We believe comparing and evaluating the similarity-identified proteins of T. boeoticum with the previously identified proteins of Aegilops tauschii, can provide a new direction to improve wheat tolerance to drought stress.

Cellular and physiological responses to drought stress in Aegilops tauschii genotypes

Drought stress is one of the most important limiting factors in crop yield through impact on the cellular and physiological functions of the plant. Therefore, the study of physiological responses of plants can help to better understanding the drought tolerance mechanisms. In this experiment, 125 wild diploid wheat genotypes of Aegilops tauschii were evaluated for the physiological responses under rainfed and supplemental irrigation conditions. The physiological characteristics such as leaf relative water content (RWC), excised leaf water retention (ELWR), relative water loss (RWL), chlorophyll a, chlorophyll b, total chlorophyll, carotenoids, ion leakage, membrane stability index (MSI) and proline content were measured. The results showed that the higher proline content, lower chlorophyll degradation rate and low amount of the membrane stability index (MSI) may inhibit the grain yield reduction under rainfed conditions. It was also found that the lower ion leakage due to the low cell membrane damage may led to the higher yield under rain-fed conditions. The results of regression analysis in both rainfed and supplemental irrigation conditions showed that proline content and total chlorophyll were introduced into the model, and explained the most variation in the grain yield. So, considering the above traits, the genotypes 16, 22, 43, 66 and 106 seems to be more drought tolerant and could be exploited in wheat breeding programs after further assessments.